Seat frame



FIG. 1 is an isometric view of a seat frame in accordance with the new design;

FIG. 2 is a front elevational view thereof,

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a left side elevational view thereof; and,

FIG. 6 is a top view thereof.

The broken lines in the figures are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a seat frame, as shown and described. 